Soaking beef in water

Unless you are getting your beef directly from a farm or butcher's truck, most blood will long have vacated the muscle. As the muscle enters rigor mortis and is (this is true for America and Europe, traditions and techniques are different in some parts of Asia and Africa) hung for the prescribed seven to ten days it loses almost all of its capillary blood.

Dry aged (not as common) beef has this effect even more, if you purchased a supermarket filet with a "sanitary pad" in the bottom, the moisture you see there is juices, water and some protein, from collapsing cells, not blood. The same is true for any beef not cooked to shoe-leather consistency, the reddish "juice" is intra-cellular and not from blood vessels.

As far as flavors go, soaking your meat for any period of time below, let's say, two days, has very little effect. It was traditionally done to apply some osmotic power to the cut in order to dilute and remove salt left over from the drying process (this was before cooling was widely available, still done in many countries outside of Europe and America), but isn't usually necessary for meat you get in the meat aisle or from your local butcher.

As far as tenderizing goes, no. Enzymatic tenderizing (that is the stuff that happens when you age beef) goes on, of course, but you won't be able to tell much of a difference between the time you bought the muscle and the time you consume it. Water itself does not tenderize. Minutes to hours do nothing.

In the west beef are not as "fresh" as in asia. The meat in the supermarket in the west most likely have been hanged and drained of any blood for several days. (Hence, there's no need to wash the blood)

In asia, at least the part where I live, the meat that I buy at 6 in the morning is coming from a cow that's slaughtered at 4.

In fact, there's a dish here that requires pre-rigor mortis meat (locally we just say to get the morning meat, meaning as fresh as possible). I've tried making this dish with the post rigor meat in the west and never quite get the right taste or texture. (I've successfully made it in Asia before)

Conversely, the pre-rigor meat here is not suitable for steak. It has a distinct beefy/cow-ey smell to it, it's very off putting to be consumed as steak. The western steak houses (the authentic and expensive ones) here usually get their beef imported from Aussie or NZ.

Yes soaking removes the blood especially when using oxtails, just try it and see how red the water gets after just an hour. Yes it changes the flavor for instance when making oxtail soup it has a clear broth with radish, if you didn’t soak the oxtails first, the broth would have an irony taste from the blood I know from experience not cooking it the right way. My mother taught me to soak the beef after that!

I was always told it’s to make the beef broth more clean tasting. I have skipped the step on one or two occasions and just skimmed the scum off the liquid, but I do find that soaking the meat beforehand does produce a clearer and better tasting broth. So when I make Korean Radish soup with beef broth base, I always soak the meat first. The radish is really light and delicate in taste so soaking the meat makes the broth taste less “intrusive,” in my opinion. Or it could be that that’s the way my grandmother always made her radish soup so I just follow. Her’s is incredible.

Amount of blood drawn out depends on how long you soak the meat for. If the beef has been bled properly when slaughtered, there is no need to "draw the blood out". If you really wanted to, you would have better results blanching it for a few minutes starting from cold water.

The blood in my opinion, doesnt really affect the flavor too much. In Chinese and Cantonese cuisine, blood (particularly duck and pig) is collected, congealed into cubes and used as a protein.

In regards to tenderizing, soaking in water does make the meat more tender, but at the cost of reducing the flavor. There are many other alternatives to tenderizing meat. Soaking in water is just not worth it in my opinion.

Additional info about meat tenderizing: Basically, all Asian restaurants use a powder, "???" in Chinese, or "Papain" which is basically a kind of papaya extract. Using this to marinate meats will make them become so tender they almost lose texture.

Some chefs will recommend using the naturally occurring chemicals in pineapple and papaya (as opposed to the chemical extract) creating a pulp and marinating the meats in the fruit pulp to create similar tenderizing effects.

You could also consider using a meat tenderizer, cutting across the grain, or ultimately choosing a more tender part of the animal.

I find that if I don’t soak my roast in water first, there is a lot of blood in the fat that I use to make gravy. This is the case with the store bought roasts I’ve had, it does not make a nice, appetizing gravy.